An electroconducting polymer having a highly grown conjugated system at the main chain thereof causes insulator-metal transition by doping with a dopant which is an electron donor or an electron acceptor, whereby the conductivity thereof can be desirably controlled. Furthermore, with the transition, optical and magnetic properties of the compound are largely changed. Accordingly, such an electroconducting polymer has been widely noticed as a functional material capable of making various functional applications by utilizing the above-described properties.
Recently, with the development of various kinds of electroconducting polymers, utilization of the conjugated electroconducting polymer to electrodes for batteries, electrochemical sensors, electrochromic devices, etc., has been highly expected.
Since conventional conjugated electroconducting polymers are generally insoluble in almost all of solvents and are not melted even by heating, the polymers had a large disadvantage of poor fabrication. Recently, electroconducting polymers soluble in solvents and fusible electroconducting polymers capable of undergoing melt molding by heating have been developed. However, it is the present status that these conjugated electroconducting polymers have not yet had sufficient fabrication, or if these polymers are given sufficient fabrication, the inherent characteristics of these compounds are impaired.
Also, when a conjugated compound is subjected to electropolymerization, a conjugated electroconducting polymer may be obtained in a film form. However, in almost all cases, conjugated electroconducting polymers keeping a film form cannot be obtained, and these compounds have a fault that they form a thin layer or deposit as a powder on an electrode.
Also, when a precursor polymer of a conjugated electroconducting polymer is cast and heat treated, a conjugated electroconducting polymer may be obtained in a film form. However, in almost all cases, it was impossible to obtain a film having sufficient flexibility. Furthermore, it has been attempted to form composites with general-purpose polymer films by utilizing electropolymerization or chemical polymerization, but there is a limitation on obtainable composites.